The existence of a light dark force mediator has been tested with the KLOE detector at DAΦNE. This particle, called U, is searched for using the decay chain ϕ→ηU, η→π+π−π0, U→e+e−. No evidence is ...found in 1.5 fb−1 of data. The resulting exclusion plot covers the mass range 5<MU<470 MeV, setting an upper limit on the ratio between the U boson coupling constant and the fine structure constant, α′/α, of ⩽2×10−5 at 90% C.L. for 50<MU<420 MeV.
Investigation at a
φ
-factory can shed light on several debated issues in particle physics. We discuss: (i) recent theoretical development and experimental progress in kaon physics relevant for the ...Standard Model tests in the flavor sector, (ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled-kaon states, (iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and
η
/
η
′ mesons, (iv) the contribution to understand the nature of light scalar mesons, and (v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the
e
+
e
−
physics in the continuum with the measurements of (multi)hadronic cross sections and the study of
γ
γ
processes.
Evolving reconstructive techniques have progressively become the preferred approach for treatment of pediatric mitral valve regurgitation. We present our experience in a cohort of patients undergoing ...surgical correction for severe mitral regurgitation. Fifty-five patients (age 1 month–18 years; median 5 years) were included in the present analysis. Different surgical techniques were used (posterior leaflet augmentation in 25, isolated cleft closure in 12, Alfieri-type procedure in 10, annuloplasty in 5, with artificial chordae in 2, and quadrangular resection with chordal transposition in 1). Follow-up time ranged from 1 to 192 months (median 38IQR 12–54 months). Operative and follow-up mortality was 0%. Reintervention in the whole population occurred in 31% of patients. However, when first surgery was performed under 2 years of age (no = 17), reintervention reached nearly 50%. The degree of residual mitral regurgitation at follow-up remained stable after surgery, while a significant increase in mean transmitral gradient was observed over time (paired
t
test = 0.03). In multivariable Cox-regression analysis, post-surgical transmitral gradient was the only independent predictor for reintervention (
p
= 0.017; HR 2.4; 95%CI 1.2–5.1), after correcting for differences in age at surgery, type of reintervention, mitral annulus dimension, and BSA at the first surgery. ROC curve demonstrated that a post-surgical transmitral mean gradient value > 5 mmHg, was predictive for reintervention (AUC = 0.89; Youden index = 0.44). Our study suggests that the use of conservative technique strategy achieves satisfactory functional results in infants and children with severe MR, although the rate of reoperation in younger patients remains substantial. Post-operative moderate mitral stenosis was the strongest predictor for reoperation.
•A bird view on Italian experience about ASR characterization and management.•A careful characterization of ASR produced by Italian shredding facilities.•Evaluation of experiences about the recycling ...of metals and material recovery from fine fraction.•Evaluation of experiences about ASR recovery as an energy source.
Automotive Shredder Residue (ASR) is a special waste that can be classified as either hazardous or non hazardous depending on the amount of hazardous substances and on the features of leachate gathered from EN12457/2 test. However both the strict regulation concerning landfills and the EU targets related to End-of-Life Vehicles (ELVs) recovery and recycling rate to achieve by 2015 (Directive 2000/53/EC), will limit current landfilling practice and will impose an increased efficiency of ELVs valorization. The present paper considers ELVs context in Italy, taking into account ASRs physical–chemical features and current processing practice, focusing on the enhancement of secondary materials recovery. The application in waste-to-energy plants, cement kilns or metallurgical processes is also analyzed, with a particular attention to the possible connected environmental impacts. Pyrolysis and gasification are considered as emerging technologies although the only use of ASR is debatable; its mixing with other waste streams is gradually being applied in commercial processes. The environmental impacts of the processes are acceptable, but more supporting data are needed and the advantage over (co-)incineration remains to be proven.
Risk Management assumed over years a central role of safe management of metro railway operation. Since exposure of passengers to hazards cannot be avoided, risk cannot be cancelled but controlled and ...brought back to acceptable levels. The quantification of system risk level and of the effects of any decision on infrastructural or operational changes must be carefully evaluated. A methodology for in-depth risk analysis within a risk-based decision management is crucial not only to identify the risk, but especially to assess and manage it. This work introduces a complete Risk Management methodology which quantitatively analyses the causes and consequences, assessing all the influence factors of metro safety. Using as example the derailment risk level, an application to an operating metro is presented assessing the effects in terms of safety risk of three different management decisions and highlighting the impact that those choices have on safety.
A
bstract
The quantum interference between the decays of entangled neutral kaons is studied in the process
ϕ
→ K
S
K
L
→
π
+
π
−
π
+
π
−
, which exhibits the characteristic Einstein-Podolsky-Rosen ...correlations that prevent both kaons to decay into
π
+
π
−
at the same time. This constitutes a very powerful tool for testing at the utmost precision the quantum coherence of the entangled kaon pair state, and to search for tiny decoherence and
CPT
violation effects, which may be justified in a quantum gravity framework.
The analysed data sample was collected with the KLOE detector at DAΦNE, the Frascati
ϕ
-factory, and corresponds to an integrated luminosity of about 1.7 fb
−
1
, i.e. to about 1
.
7 × 10
9
ϕ
→ K
S
K
L
decays produced. From the fit of the observed ∆
t
distribution, being ∆
t
the difference of the kaon decay times, the decoherence and
CPT
violation parameters of various phenomenological models are measured with a largely improved accuracy with respect to previous analyses.
The results are consistent with no deviation from quantum mechanics and
CPT
symmetry, while for some parameters the precision reaches the interesting level at which — in the most optimistic scenarios — quantum gravity effects might show up. They provide the most stringent limits up to date on the considered models.
Abstract
OBJECTIVES
Management of resternotomy is often a difficult challenge in patients with congenital diseases who have undergone multiple sternotomies. Our goal was to report our single-centre ...experience with carotid cannulation using a graft interposed during redo sternotomy in complex cardiac reintervention procedures.
METHODS
We performed a retrospective review of all patients who had undergone complex redo sternotomies between January 2019 and May 2020 utilizing a cervical cannulation technique with a Gore-Tex graft interposed on the carotid artery. We classified our population study on the basis of the primary diagnosis and the type of surgery. The primary outcomes of our analysis were the evaluation of the safety of the procedure in terms of survival and freedom from neurological events.
RESULTS
We analysed 22 patients who had undergone previous complex operations. The median age and weight at the time of reintervention were 130.35 (range 0.46–435) months and 31.5 (range 2.2–85) kg, respectively. Composite graft carotid cannulation provided adequate arterial flow in all patients with a median arterial flow of 3.5 l/min/m2 (range 0.6–6). One major cardiac injury occurred during sternotomy when emergency cardiopulmonary bypass (CPB) was initiated. Moreover, during their hospital stays, all patients had an uneventful recovery without neurological or vascular complications and no cervical wound infections.
CONCLUSIONS
Carotid cannulation using interposition of a side graft on the common carotid artery for arterial inflow is a reliable and safe method for initiation of CPB in complex redo surgeries in patients with congenital disease. Complications directly associated with this type of cannulation are uncommon and allow surgical re-entry with overall low risks.
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